Revenue, costs, profit and break-even

Which of these is a fixed cost for a bakery?

What are variable costs?

A juice bar sells 1,250 smoothies in a month at £6 each. What is its revenue for the month?

A candle maker has fixed costs of £4,000 a month and a variable cost of £2.50 per candle. What are its total costs when it makes 1,200 candles?

A phone case seller sells 800 cases at £15 each. Fixed costs are £5,000 and the variable cost is £9 per case. What is the result?